Brief Scientific Reports
Glandular Inclusions in Inguinal Hernial Sacs
and Spermatic Cords
MCillerian-like Remnants Confused with Functional Reproductive Structures
ANNA NIELSEN WALKER, M.D. AND STACEY E. MILLS, M.D.
Small, glandular inclusions are present in approximately 6% of
hernial sacs from prepubertal males. Identical structures may
be present in the spermatic cord. Histologically, these are composed of ciliated, low columnar epithelium with eosinophilic
cytoplasm and basal nuclei. A mantle of fibrous tissue surrounds
each gland-like structure. These epithelial inclusions may be
confused with reproductive ducts of functional importance; however, specific histologic features allow ready distinction. The
origin of these structures is uncertain, but it is most probable
that they are remnants of Miillerian ducts. (Key words: Hernial
sac; Spermatic cord; Miillerian-like inclusions; Miillerian duct;
Herniorrhaphy) Am J Clin Pathol 1984; 82: 85-89
SMALL GLANDULAR INCLUSIONS occasionally are
found in inguinal hernial sacs and spermatic cord tissue
from young males. These structures are lined by ciliated
columnar epithelium and are surrounded by a rim of
condensed fibrous tissue of variable thickness. Many surgical pathologists are unaware of these apparently normal
structures, and they are not described in textbooks of
surgical pathology. 7,810 " The inclusions may be misinterpreted as portions of the vas deferens or epididymis
and lead to the erroneous conclusion that a functional
reproductive structure has been disrupted. The purpose
of this study is to define the histologic features of these
inclusions, differentiate them from male reproductive tract
structures, determine their frequency in the surgical population, and discuss their possible origin.
Departments of Pathology, Medical Center of Central
Georgia, Macon, Georgia and University of Virginia Medical
Center, Charlottesville, Virginia
the authors (SEM) at the University of Virginia prior to
the initiation of this study. All of these were from prepubertal males. To determine the frequency of the inclusions in the general male population undergoing inguinal hernial repair, the slides from 100 consecutive herniorrhaphies at the Medical Center of Central Georgia
were reviewed. Blocks were available on all cases. Periodicacid Schiff (PAS) stains and Masson-trichrome stains were
performed on each specimen with gland-like inclusions.
Examples of vas deferens, epididymis, appendix testis,
appendix epididymis, and paradidymis were available for
histologic comparison with the glandular inclusions. PAS
and Masson-trichrome stains also were performed on
these sections.
Results
Clinical Features
Materials and Methods
Eight inguinal hernial sacs and two spermatic cords
with gland-like inclusions had been collected by one of
Received September 18, 1983; received revised manuscript and accepted for publication January 17, 1984.
Dr. Mills is an American Cancer Society Junior Faculty Clinical Fellow.
Address reprint requests to Dr. Walker: Department of Pathology,
Medical Center of Central Georgia, 777 Hemlock Street, Macon, Georgia
31208.
85
The initial 10 patients were prepubertal and ranged in
age from three weeks to eight years. Eight patients had
undergone elective inguinal herniorrhaphy for unilateral
or bilateral inguinal hernias. Two boys had coexisting
hydroceles. One patient had undergone bilateral inguinal
herniorrhaphy and orchiopexy for cryptorchidism. The
final patient had undergone unilateral orchiectomy for a
testicular endodermal sinus tumor.
The 100 consecutive herniorrhaphy patients ranged in
age from newborn to 83 years. Fifty-two patients were
older than 15 years and 48 were 15 years old or younger.
Fifteen years is the age by which the majority of American
86
AND MILLS
A.J.C.P.-July 1984
males will have experienced the onset of puberty.13 Glandular inclusions were found in specimens from three of
the 100 patients. All three were prepubertal, being six
years, four years, and 10 months of age. The six-year-old
had a hydrocele removed as well. The frequency of glandular inclusions in hernial sacs from prepubertal males
was thus approximately 6% in our series.
Microscopic Features
The inclusions were round to irregularly elongated
glandular structures embedded in the fibrous connective
tissue of the specimens (Fig. 1). They ranged in size from
70 to 600 fim and frequently were associated with small
blood vessels. In most specimens, only one or two inclusions were seen, but, occasionally, a dozen or more were
present in close proximity (Fig. 2). Vas deferens or epididymis was not present in any of the sections. The lining
epithelium of the glands predominantly was composed
of ciliated, low columnar cells with eosinophilic cytoplasm
and basally oriented nuclei (Fig. 3). Occasional cuboidal
cells with pale eosinophilic cytoplasm and round nuclei
were interspersed among the columnar cells. In some
inclusions, the cells were crowded and appeared to form
a bilayer. The nuclei were darkly staining and rarely possessed a single small nucleolus. There was no cytologic
atypia and mitoses were not present. The inclusions were
surrounded by a variably thick condensation of elongated,
FlG. 1 (upper). Hernial sac inclusions consist of irregular glands
surrounded by a cuff offibroblasts.Hematoxylin and eosin (X145).
FIG. 2 (lower). Multiple glandular inclusions occasionally form closely
packed aggregates, leading to confusion with epididymis. Hematoxylin
and eosin (X55).
FIG. 3. Glandular epithelium is composed of columnar to cuboidal
cells with uniform nuclei, occasional nucleoli and prominent cilia. Hematoxylin and eosin (X700).
BRIEF SCIENTIFIC REPORTS
Vol. 82 • No. 1
spindled cells producing a connective tissue mantle
(Fig. 1).
Masson trichrome staining revealed that the connective
tissue surrounding the inclusions was composed entirely
of fibroblasts without a smooth muscle component. Normal vas deferens and epididymis demonstrated wellformed smooth muscle coats. An appendix epididymis
revealed scattered smooth muscle cells intermixed with
a predominantly fibroblastic mantle; the connective tissue
component of a paradidymis had a similar composition.
The connective tissue core of an appendix testis contained
only fibrous tissue. Some of the inclusions contained
amorphous eosinophilic material in their lumens. One
inclusion had an associated psammoma body.
Periodic acid-Schiff staining of the inclusions revealed
a faint positivity to the apical epithelial cytoplasm and
a strong positivity to the intraluminal amorphous material. The lining epithelium of vasa deferentia did not
stain with the PAS stain. Epididymal tubular epithelium,
appendix epididymis, and paradidymis epithelium, however, also were faintly PAS positive, as was the surface
epithelium of an appendix testis.
Discussion
Glandular inclusions in hernial sacs and spermatic
cords from prepubertal males can be distinguished histologically and anatomically from both functional reproductive structures and paratesticular wolffian vestiges. A
Masson-trichrome stain is helpful in this evaluation, but
PAS staining provides no more information than sections
stained routinely with hematoxylin and eosin. The ciliated
eosinophilic columnar epithelium and fibrous mantle
lacking smooth muscle give the inclusions a distinctive
microscopic appearance.
Functional glandular or tubular structures to be considered in the differential diagnosis of the inclusions that
we describe include the epididymis, vas deferens, tubuli
efferentes, tubuli recti, and rete testis. The epididymis
consists of multiple, closely arranged tubules lined by tall
columnar epithelium with pale cytoplasm and surrounded
by circularly arranged smooth muscle cells. The epithelial
cells do not bear true cilia but may possess attenuated
microvilli or "stereocilia" that can resemble true cilia by
ordinary light microscopy.3 The cytoplasm of the epithelial
cells is paler than that of the inclusions, and the presence
of smooth muscle in the epididymal tubular walls also
helps distinguish them from the glandular inclusions.
Moreover, the inclusions, even when multiple, do not
demonstrate the orderly, tightly packed tubules of the
epididymis.
The vas deferens is lined by epithelium that ranges
from cuboidal to columnar of a type like that of the
epididymis.3 In addition to its epithelial differences, the
87
EFFERENT
DUCTULES
ABERRANT
DUCTULE
«UCT or EPioiorms
DUCTUS
HULLERIAM
SEMINAL
DEFERENS
DUCT
VESICLE
FIG. 4. Genital system of the male fetus; the solid black line
indicates the location of the Mullerian duct.
thick muscular wall of the vas deferens gives it a histologic
appearance that is quite different from the glandular inclusions.
The most cephalad functional reproductive structures
in the scrotum that possess true ciliated cells are the tubuli
efferentes. These small conduits are lined by clumps of
tall columnar, ciliated cells interspersed with nonciliated,
low cuboidal epithelium. This combination results in a
unique histologic appearance. 3 Their protected location
between the testis and the epididymis makes it quite unlikely that the tubuli efferentes would be transected unwittingly. The same can be said regarding the tubuli recti
and rete testis. Moreover, these structures are lined by
low cuboidal epithelium unlike that of the inclusions.
There are four vestigial scrotal structures associated
with the tunica vaginalis and apparently derived from
the mesonephros or wolffian body that may be confused
with the inclusions we describe.1 Three are attached to
the epididymis: the appendix epididymis and the cranial
and caudal aberrant ductules. The appendix epididymis
is a minute (2-3 mm), usually cystic structure lined by
vacuolated secretory epithelium and connected to the
head of the epididymis by a stalk.4 The stroma surrounding the cyst may contain scattered smooth muscle cells
as described above. Both aberrant ductules are blind tubules of variable epithelial composition. The paradidymis
is the fourth and most cephalad vestige and consists of
a small collection of tubules attached to the spermatic
cord at the level of the head of the epididymis (Figs. 4
and 5). These tubules may be detectable only microscopically and are lined by ciliated columnar cells.6-914
The origin of the distinctive glandular inclusions that
we describe is uncertain and we have considered three
possibilities. Although the location of the paradidymis
makes it unlikely that it would be excised during an inguinal hernia repair, the excision of a hydrocele or portion
of the spermatic cord might include that structure. This
A.J.C.P. • July 1984
WALKER AND MILLS
88
OBLITERATED
VAS
HULLER1AN
DUCT
DEFERENS
FIG. 5. Genital system of the postnatal male;
the broken line indicates the location of the
obliterated Miillenan duct.
APPENDIX
EPIDIDYMIS
APPENDIX
TESTIS
TESTIS
CRANIAL
-CAUDAL
ABERRANT
ABERRANT
DUCTULE
DUCTULE
(AFTER
explanation would not account for the inclusions found
in the hernial sacs when the excisions were cephalad to
the head of the epididymis, In addition, the paradidymis
that we examined had a muscular component to the surrounding stromal cuff, unlike the glandular inclusions.
Another possible origin for the glandular inclusions is
ciliated cell metaplasia of pinched-offmesothelium, analogous to peritoneal endosalpingiosis in the female.5
Psammoma bodies haye been observed in peritoneal endosalpingiosis, and we found one gland-like inclusion
with an associated psammoma body. We have seen endosalpingiosis in hernial sacs from female patients, but,
in our experience, this process lacks the fibrous connective
tissue condensation that is a distinctive component of
the inclusions in males.
The final and, in our view, most likely explanation for
these glandular inclusions is that they represent vestiges
of the Miillerian duct. In the male fetus, the Miillerian
ducts run in close proximity to the wolffian ducts but
begin to degenerate during the third month (Figs. 4 and
5). Only their extreme cranial ends, the appendices testes,
consistently persist into adult life. The latter are small
(2-3 mm) nodules of connective tissue lined by ciliated
columnar epithelium4 and located at the upper pole of
each testicle.' Other remains of the Miillerian duct were
found by Watson in his study of testicles from sevenand nine-month male fetuses." He identified Miillerian
duct remnants along the anterior and outer border of the
epididymis. These glandular structures were surrounded
by a sleeve of connective tissue identical to that seen
around the inclusions we describe. In older infants, children, and adults, he did not find such well-preserved
structures but did describe "small vessels and fissures"
in the area where the duct remnants were found in fetuses.
AREY)
Sundarasivarao examined testes and epididymides from
autopsies and found tubular remnants of the Miillerian
duct in the stroma of appendices testes. These, too, consisted of cuboidal or columnar epithelium surrounded by
a condensation of cellular fibrous tissue; a histologic appearance that he likened to that of the fallopian tube. He
also identified Miillerian remnants in the loose connective
tissue between the epididymis and testis. The more proximal tissues along the spermatic cord were not examined
for Miillerian residua.12
The glandular structures that we studied occur in an
appropriate anatomic area for Miillerian duct remnants,
in close proximity to the vas deferens. Their epithelium
resembles that of known Miillerian structures, including
the fallopian tube and appendix testis, and they have the
fibrous mantle seen in fetal Miillerian duct remnants. 15
No other normal structure with similar histology has been
described in the male inguinal canal, and we have not
observed gland-like inclusions of this type in inguinal
hernial sacs from females.
The presence of microscopic Miillerian-like inclusions
in hernial sacs from males should not be confused with
the persistent Miillerian duct syndrome—a condition in
which grossly visible rudimentary fallopian tubes and a
uterus are found in an otherwise normal, genotypic male.
This syndrome is believed to be due to an inherited deficiency in the production of or response to Miillerian
inhibiting factor.2
Regardless of their cellular origin, the inclusions that
we describe are common findings in hernial sacs and
spermatic cord tissue from prepubertal males. They are
of no clinical importance except for their potential for
confusion with functional reproductive structures. The
fact that they are only found in prepubertal males suggests
BRIEF SCIENTIFIC REPORTS
Vol. 82 • No. 1
that these structures may degenerate during adult life,
perhaps at an accelerated rate after puberty.
Acknowledgment. The authors thank Paula Carroll for her artistic
assistance.
References
1. Arey LB: Developmental anatomy. A textbook and laboratory
manual of embryology. Seventh edition. Philadelphia, WB Saunders, 1974, pp 308-341
2. Barriola M, Jimenez J, Gutierrez-Hoyos A, Tovar JA: Cryptorchidism and persistence of Mullerianremnantsin a normal male.
Z Kinderchir 1981; 33:369-372
3. Bevelander G: Essentials of histology. Sixth edition. St. Louis, CV
Mosby, 1970, pp 249-250
4. Bloom W, Fawcett DW: A textbook of histology. Eighth edition.
Philadelphia, WB Saunders, 1962, pp 572-573
5. Burmeister RE, Fechner RE, Franklin RR: Endosalpingiosis of the
peritoneum. Obstet Gynecol 1969; 34:310-318
89
6. Cattolica EV: Torsion of the paradidymis. Urology 1974; 4:726727
7. Coulson WF (ed): Surgical pathology. Philadelphia, JB Lippincott,
1978
8. Dehner LP: Pediatric surgical pathology. St. Louis, CV Mosby, 1975
9. Rolnick D, Kawanoiie S, Szanto P, Bush 1M: Anatomic incidence
of testicular appendages. J Urol 1968; 100:755-756
10. Rosai J: Ackerman's surgical pathology. Sixth edition. St. Louis,
CV Mosby, 1981
11. Silverberg SG (ed): Principles and practice of surgical pathology.
New York, John Wiley and Sons, 1983
12. Sundarasivarao D: The Mullerian vestiges and benign epithelial
tumors of the epididymis. J Pathol Bacteriol 1953; 66:417-432
13. Vaughan VC, McKay RJ: Nelson's textbook of pediatrics. Tenth
edition. Philadelphia, WB Saunders, 1975, p 1293
14. Warwick R, Williams PL: Henry Gray's anatomy, descriptive and
applied. 35th British edition. Philadelphia, WB Saunders, 1973,
p 1344
15. Watson JH: Some observations on the origin and nature of the socalled hydatids of Morgagni found in men and women, with
especial reference to the fate of the Mullerian duct in the epididymis. J Anat Physiol 1902; 36:147-161
Interference of O.C.T.® Embedding Compound
with Hormone Receptor Assays
HELMUT MUENSCH, M.D., PH.D. AND WILLIAM C. MASLOW, M.D.
The interference of O.C.T.® (Optimum Cutting Temperature)
embedding compound with the determination of estrogen and
progesterone receptor analysis in rabbit uterus cytosol and human
breast cancer tissue was investigated. It was determined that
O.C.T. Compound reduces binding in rabbit uterus cytosol at
concentrations greater than 1%. Hormone receptor binding
greatly was reduced in human breast cancer tissues from O.C.T.
embedded tissues when compared with the untreated tissue of
the same patients. Progesterone receptor binding was affected
more strongly than estrogen binding. (Key words: Hormone receptors; Estrogen receptor; Progesterone receptor; Breast cancer,
O.C.T. compound; Frozen section) Am J Clin Pathol 1984; 82:
89-92
ESTROGEN AND PROGESTERONE receptor measurement (ER, PR) in carcinoma of the breast has become
an established predictor of prognosis and response to endocrine therapy.',3'7 Most commonly, the standard technic
used for the measurement of the receptors is the dextrancharcoal assay.4 This assay simultaneously provides two
parameters of information, the disassociation constant
(Kd) and the maximum binding (Bmax). The perforReceived August 29, 1983; received revised manuscript and accepted
for publication October 24, 1983.
Address reprint requests to Dr. Muensch: Department of Clinical
Pathology, City of Hope National Medical Center, 1500 East Duarte
Road, Duarte, California 91010.
Department of Clinical Pathology, City of Hope National
Medical Center, Duarte, California
mance of the dextran-charcoal assay depends on a number of variables, such as handling of the tissue, the storage
conditions of the tissue, homogenization procedures,
protein concentration of the cytosols, receptor stabilizing
agents, quality of radioactive tracers, and incubation conditions.
We have encountered another factor that may influence
the receptor assay. Because of increased cancer awareness
among the population breast cancer is diagnosed at earlier
stages. Consequently, tissue samples have become progressively smaller. The only tissue that may be available
for hormone receptor analysis may be the piece that has
been embedded for the frozen section in O.C.T. Compound. This piece, properly trimmed or untrimmed, then
is submitted to the laboratory for hormone receptor analysis. In our own experience, and through conversations
with representatives from commercial laboratories, it became evident that O.C.T. Compound-embedded tissues
quite frequently are submitted for hormone receptor
analysis. We found the O.C.T. embedding compound to
cause very significant interference in the receptor assay.